添加不同化合态结合的铜离子对其在黄土中吸持及形态的影响

EFFECTS OF ADDING COPPER OF DIFFERENT CHEMICAL FORMS ON ITS SORPTION AND SPECIATION BY LOESS

分别以CuSO4 和Cu(NO3 ) 2 为吸持质 ,研究了添加不同化合态结合的铜离子在黄土中的等温吸持及形态分布规律 .结果表明 :黄土吸持铜离子以碳酸盐结合态为主 .当铜离子初始浓度较低时 ,添加不同化合态结合的铜离子对其在黄土中的吸持及碳酸盐结合态没有明显影响 ;当铜离子初始浓度超过一定值时 ,添加不同化合态结合的铜离子对其在黄土中的吸持及碳酸盐结合态的影响随铜离子初始浓度的增加而明显增大 .添加不同化合态结合的铜离子 ,其吸持量和碳酸盐结合态含量均随土壤浓度的增大而减小 .当铜离子初始浓度较低时 ,添加不同化合态结合的铜离子对其在黄土中的吸持量及碳酸盐结合态含量随土壤浓度的变化影响不大 ;当铜离子初始浓度超过一定值时 ,相同初始浓度条件下CuSO4 较Cu(NO3 ) 2 会造成更大幅度的变化 .

Experiments on copper sorption and chemical speciation by loess were conducted,taking CuSO 4 and Cu(NO 3) 2 as adsorbent,respectively.The results demonstrate that copper bonded to carbonates is dominant in the copper sorption by loess.Adding copper of different chemical forms has little effect on copper sorption and bonded to carbonates when copper initial concentration is low.Upon the copper initial concentration exceeding certain value,the effect of adding copper of diffe- rent chemical forms on copper sorption and bonded to carbonates would increase apparently with increasing initial concentration of copper.Both copper sorption and bonded to carbonates adding copper of different chemical forms decrease with increasing soil concentration.However,the difference of copper sorption and bonded to carbonates in terms of different chemical forms could be found as copper initial concentration is greater than certain threshold,and CuSO 4 would lead to much significant change than Cu(NO 3) 2.